Collaborating across tiers: rethinking digital language teacher education via virtual exchange

Cross-tier collaboration between pre-service teachers (PSTs) and in-service teachers (ISTs) remains underexplored in online teacher education, particularly within computer-assisted language learning (CALL). This practice-oriented study aimed to examine how a structured virtual exchange (VE) model can facilitate effective cross-tier collaboration and professional learning. The study was conducted within the Erasmus + KA3 VALIANT project and involved 16 PSTs from a German university and 13 ISTs from different European countries who collaborated over an eight-week period. Participants engaged in multilayered interactions (PST–PST, PST–IST, and IST–IST) to co-design and implement technology-enhanced lessons addressing authentic CALL-related challenges. Grounded in a sociocultural perspective on teacher development, the VE emphasized strategic mediation, with ISTs supporting PSTs’ learning within their zones of proximal development. Adopting a qualitative case study design, the study investigated participants’ perceptions of the key features of the VE that facilitated effective collaboration. Data were collected through open-ended surveys, Zoom session recordings, and co-created lesson materials, and analyzed using thematic analysis. The findings indicate that effective PST–IST collaboration was supported through the co-construction of knowledge via collaborative problem-solving and sustained feedback, as well as through shared responsibility and distributed expertise. In addition, ISTs highlighted the value of IST–IST collaboration, particularly opportunities for peer learning and professional growth across diverse educational contexts. The study also identified affordances and challenges associated with facilitating multilayered VE collaboration. Overall, the findings provide practical insights into how pedagogically grounded VEs can foster reciprocal mentoring and professional growth in CALL teacher education.